Traditional roller skates, and more recently, inline roller skates, are popular among children and adults alike. While originally intended for roller rinks and the like, modern roller skates commonly employ rollers with a rubber-like covering which permit them to be used on roadways, sidewalks and other outdoor surfaces. One issue with these types of roller skates is that they may only be used for skating. If an individual is using the roller skates outdoors, he or she must either carry a pair of walking or running shoes, or return home, when finished skating because its is difficult to walk around in such skates.
This problem has been addressed at least to some extent in the prior art. In one design, the outsole of a shoe is formed with one or more cavities which receive rollers capable of moving between an extended position in contact with the ground or other surface and a retracted position inside of the outsole. See, for example, U.S. Pat. Nos. 6,474,661; 6,523,836; 5,797,609 and 5,785,327. These types of shoes may be used as a roller skate with the rollers extended, but can function as a walking or running shoe by retracting the rollers within the cavities. This versatility provides an advantage over traditional roller skates or inline skates, but also creates problems. In particular, shoes of this type are relatively heavy when worn as a walking or running shoe due to the presence of multiple rollers in the shoe outsole. Additionally, the outsole must be made relatively thick to receive the entirety of the rollers when in the retracted position which adds weight to the shoes and detracts from their aesthetic appearance.
Another approach in the prior art is to provide a shoe with a detachable skate. For example, U.S. Pat. Nos. 6,736,411 and 6,120,038 disclose shoes which may be releasably attached to an inline roller assembly to covert the shoe from a conventional walking or running shoe to a roller skate. U.S. Pat. Nos. 6,729,629 and 6,702,304 teach the combination of a shoe and a roller base having a platform with a pair of rollers at either end. The shoes of these two patents may be releasably attached to the roller base, and detached, depending on whether they are to be used as roller skates or walking shoes. Limitations with both of these designs include the fact that both the inline roller assembly and the roller base are relatively cumbersome to attach and detach from the shoe, and they are inconvenient and heavy to carry around after conversion from a roller skate to a walking shoe.